Turn sliders up to 100 for you and 0 for the CPU. A breakaway is when you are the first player to carry the puck into the defensive zone while there are no players of the opposing team in the zone. i would just skate behind your own net, use RT for speed burst and quickly pass it up ice past the other team. If you aren't the first into the zone, just retreat and try again.
When you get in on the goalie you can score pretty easily by deking to the backhand or just going backhand to forehand in the slot.